Crushing machinery



Nov. 28, 1939. s. sTEARNs- CRUSHING MACHINERY Filed Nov. 10, 1956 7 sheets-s e t 1 Nov. 2 1939. s. STEARNS 2.181571 CRUSHING MACHINERY File d Nov; 10, 1956 7 Sheets-Sheet 2 s. STEARNS I W NG MACHlNERY I Filed m 10'', 1956 7 sheets sheei 4 Nov. 28, 1939. s, STEARNQ 2,181,571

oausnme MACHINERY Filed Nov. 10, 1936 '7' Sheets-Sheet 5,

H l; l n In f Patented Nov. 28, 1 939 UNITED STATE 5 P TENT- OFFICE? I j 2,181,571 I, I, CRUSHING MACHINERY Sheldon Stearns, Westfield, N. J. Application November 10, 1936, Serial No. ,110,0'35

9- Claims.

- My invention relates to improvements in crushing machinery, in particular to the type of crushing machinery known as gyratory crushers in whichmaterialis crushed in two or more stages as fully described in my patent application, Serial #238,016, filed August 27, 1935, which issued as Patent 2,147,721on'February 21, 1939. I

In such a multi-stage gyratorycrusher there are two or more centrally located conical crushing heads mounted upon a vertical shaftQv'One end of this vertical shaft is gyratedby means of an eccentric driven directly or indirectly by a motor. The other end of the shaft is centrally and pivotally mounted. Surrounding these conically shaped heads are stationary concaves or crushing surfaces so shaped as to form a large entrance opening between each conical head and its concave at the top, and a continuously narrowing space between each head and its concave towards the lower or discharge end. The shaft with is heads does notrevolve, but is so gyrated that the heads move towards and away from their concaves at: every point of their circumference, once for every revolutionoi the eccentric. The minimum clearance between each of the heads and their corresponding concaves motion of the heads, untilit'is finally discharged from the last stage of the crusher. In other words, the first crushing stage serves to crush the materialfromits original sizeto some definite intermediate size, and is discharged from the first crushing stage and allowed to enter the secondcrushing stage. Two or more stages are used for crushing the material'from its original size to the desired final size. The clearance between the concave and the crushing head of the first stage at their discharge ends is so de: signed that it does not pass more material at that point than can be accommodated or crushed during an equal interval of time in the secondcrushingstage. If the crushing of the material is accomplished in' more than two stages, the clearance between the concave and the crushing heads at their discharge ends ofeach crushing stage .is so proportioned that it does notv pass more material than can be crushed in an equal interval of time in the succeeding stage. Material 7 rial has been crushed to still smaller dimensions and some of it might even be to a finenesssmaller than'the desired fineness from the last crushing stage. The actual percentages of various sizes of the material as it is discharged from the first stage depends upon the friability of the material crushed. I

I have'found that if this undersize material continues to passthrough succeeding stages a portion of it is crushed still finer in each successive stage,fand thus will produce a final crushed material which may contain too great a percentage of material reduced in size below the final degree-of fineness.

To overcome this disadvantage, I have placed between crushing'stages screens or grids forseparati'ngthese fines from the coarse material. These screens or grids are mounted on the top of the gyrating heads so that they are a part rectly, below, the screens. In this manner the I fines are made to "by-pass the-next succeeding "crushing stage or stages. In most all gyratory crushers vibrations exist during the crushing operation. These vibrations are transmitted to the screens and give them a vibratory motion similar to the vibrating screens/commonly used for screening crushed material.

Hence, by gyrating and vibrating the screens I not only secure efiicient-screening but it also permits positioning the screens 'at a small angle to the horizontal and still have them capable of delivering the oversize material remaining on the screens to the receiving opening of the succeeding stage. r I 1 In order to secure as great a screen area as possible, I also provide a chute or conveying surface on which the discharged material from a ,preceding stage may drop and which conveys the material/to the screen below it as close to the gyratingjshaft as possible. This conveying surface is fastened to the bottom of the head of that crushing stage from which the material is being discharged so as to give this conveying surface a gyratory and vibratory motion which assists so greatly in moving the material over the conveying surfaces.

It should be .noted howeverthat where the difference of diameters between the discharge of any stage and the intake oi the succeeding stage is sufllcient to provide ample screen area the above mentioned chute or conveying surface can be omitted and the material discharging from any stage may drop directly upon the screen.

It is not necessary to have the screen area so great as to screen between crushing stages all or nearly all the fines from the coarse material, because merely scalping, that is, only partially screening the material, produces improved results.

When employing more than two crushing stages it may be found more economical to omit screening between certain stages and have screening between the other stages, that is, the screened material by-passes only some of the stages. It also might be found advantageous when crushing certain material in more than two stages to screen out between the first and second stages not only the fines that have been reduced to the final desired sizes but also the material that has been reduced to a sizebelow the minimum clearance of the second crushing stage, allowing the succeeding screens to introduce the material larger than the final size to a succeeding crushing stage for further reduction.

In place of using a single screen, the well known principle of multiple deck screens may be employed so as to secure more eflicient screening.

In order to have screening effective it is necessary to make the heads with sufiicient openings through them to allow thescreened product to readily drop through these openings to the space below that particular head. In this manher. a part of the material passing through the crusher by-passes certain crushing stages.

In order to protect the heads from wear, especially at the openings through which the screened material drops, these exposed surfaces of the head should be lined with wear resisting material.

Placing these openings in the 'heads to allow screened material to drop through them also has the advantage that these gyrating heads can be made lighter.

In using screens between stages the material passing through the screens by-passes the crushing stage directly following the screen. This results in a multi-stage crusher in which the earlier stage or stages have more material passing through the crushing chambers than passes through the later stages in which the screens by-pass some of the material.

As the last stage of my multi-stage crusher may be used for producing quite fine material there is a decided advantage in removing the material already reduced to the desired fineness before the material enters the last stage. The material entering this stage has smaller voids than the material had in the previous crushing stages. size or even smaller than the final size are permitted to enter the receiving opening of the last stage this fine material may fill up the voids existing between the material requiring crushing in that stage. This makes the final crushing more difiicult, requires more power and produces still more fines of smaller size than the desired final degree of fineness. There is also the danger of producing packing of the material in this last stage, 2111 of which could be largely prevented by screening the material before it enters the last stage of the crusher.

In a multi-stage gyratory crusherof my invention, I can also permit the crushing of two If the fines already reduced to the final or more different sizes of material without having the finer material pass through the earlier stage or stages of the crusher. Finer material may be introduced through suitable openings in the frame of the crusher leading to later crushing stages, and thereby by-passing the earlier stages of the crusher. For example, many gyratory crushers of the present single stage type have oversized material discharged from them.

The crushed material is screened and the oversized is returned to the crusher to be crushed over again. In a multi-stage crusher of my invention this oversized material can be returned to the inlet opening of the last stage through suitable openings in the frame of the crusher and crushed to the desired final size without having to be readmitted to the crusher with the initial coarse feed. This means that some of the material finally discharged by the crusher does not pass through all the crushing stages, the earlier crushing stages being by-passed.

I also provide suitable hand holes to permit taking out of samples of the crushed material between crushing stagesso that the size of material produced by any stage may be determined. Naturally, these hand holes can also be used for visual inspection as, for instance, checking the discharge clearances between head and concave.

Screening the material between stages relieves certain crushing stages from being burdened with the full quantity of the material initially introduced into the crusher. This, in certain cases, permits reducing the diameter and area of crushing surfaces thereby reducing the over all dimensions of the crusher. There 1' also a saving in power. by not having to crush material already to desired size to a still finer size.

An important object of my invention is the production of more finished product of the desired size and less product smaller than the desired size.

Another important object of my invention is to relieve any one crushing stage of crushing material already to the size of smaller than the size of the minimum discharge opening of that stage, thereby permitting the use of a. crushing stage of smaller capacity.

Another important object. of my invention-is in decreasing the power consumption of the crusher chiefly because there is less power wasted in crushing below the desired degree of fineness.

An important advantage of my invention lies in the fact that the crusher can crush different sized materials Without having the finer material pass through the earlier stages of the crusher, thereby also saving in power consumption.

Another important advantage of my invention lies in the fact that samples of crushed material may be obtained from between crushing stages so that if the minimum discharge clearance has been changed due to wear or other causes, this dimension can be reestablished.

Another advantage of my invention lies in the fact that suitable hand holes or peep holes permit of visual inspection of the crushing chambers even during the operation of the unit.

Another advantage of my invention is that it permits wet crushing in the latter stages of the crusher.

For a more detailed understanding of my 1nvention reference is to be made to the following description and accompanying drawings of practical embodiments of the inventive idea, and in which drawings-- v Fig. l is a part sectional view of a three stage screen arrangements 'In the vfigure screentl is. made'in. three parts.

gyratory crusher showing particularly the crush.- ing surfaces, thecrushing chambers andthe between stages.

Fig. 21s a sectional view to an enlarged scale of the crushing surfaces and screen arrangements of a three stage gyratory crusher.

Fig. 3 is a sectional view along. the, lines 3-3 for Fig. 2. Y

- Fig. 4 is a sectional detail view of the ribs or arms between the hub and rim of a gyrating head provided with screens, along-thelines 4-4 of Figs. 2 and 3;

and second stages for driving shaft 2 to -pass tact, and

Fig. .5 is a sectional view like that of Flg. ;2

except it shows the use of double deck screens. Fig. 6 isapartsectional view of a two stage gyratory crusher having screens'betweenthe first screening out finished product without using the conveying surfaces illustrated in the previouseiigures.

Fig. '7 :is apart sectional view like Fig. 2 but showing the. method of "introducing between stages additional material to be crushed.

Fig.8 is a part sectional view along the lines 8-8 of Fig. 'I. g Fig.9 is a sectional view along the lines 9-8 I of Fig. 8 showing particularlyin detail-the design and location of hand holes or peep holes.

Referring to Fig. l the electric motor for driving the crusher is shown at This motor drives the vertical shaft 2'through the coupling 3. The lower end of the vertical shaft'2 is fastened .to an eccentric bushing 4. The outer'surface of .the eccentric bushing'is journalledina station- .ary frame 5, and 'tric bushing rotates about the hollow gyratlng the inner surface of the eccenshaft 6. This 'hollow'gyrating shaftpermits the through it without concarries the crushing "heads I, '8 and 9 portion. The gyrating is centered andpivoton its enlarged tapered shaft 6 near its upperend ally mounted on aball seated bearing Land is the gyrating shaft supported at its threaded :upper portion. by the nut 11. The motor in .tur'n'ingthe shaft '2 rotates the eccentric *4, which in turn oscillates 8 about fits "upper and centrally located pivot ID. The weight of the motor and that of all the rotating and gyrating parts are carried by'the spider casting l2 mounted upon the stationary frame with the conical heads .1, 8 Band Scanbe raised or lowered by'means of the adjusting nut ll. Frame 3'is suspended by a number of suspension wire ropes H from a fixed support above the crusher and'not shown'in the figure. Surrounding" the crushing heads 1, 8 and Bare concaves I5, l6 and I1. These concaves are :in the form'of a continuous ring casting and 1 are separately mounted in the stationary supporting frame l3.

As shown in Fig. 1, and to .an enlarged, scale in Fig.2 the clearance spacesbetween'the crushing heads and their corresponding concaves of any stage are larger at their top than at their bottom or discharge ends. Material is introduced into the space at the topbetween the "crushing head 1 and concave |5.=and.most of :it

is crushed to the size of the minimum clearance between thishead and its concave at their dis-v charge ends.."The material is then guided by the chute or conveying surface l8. ,This conveying surface 18 is a part of the casting l-9 fastened to the lower side of thehead 1. Casting l9 has a centrally'located opening 20 through which the material drops to thescreen 2| mounted on the top of the succeeding head '8. "The screens are made in several .parts for ease of I assembly.

.cep't the material which screen 2|.

tened-to the upper surface of the arms of heads by screws 3|l.and the conveying casting is fastened to the .lower surface of these arms by It. Shaft 8 together" l2l" :to'do more efilcient screening.

Screenf2l slopes outwardly, and as conveyinz casting 19 .and screen2| are .gyrated and vibrated, material will move along surface .|8 inwardly and along screen 2| outwardly to the receiving the second stage of the crusher expasses through the The material passing through screen 2| drops through openings in the gyrating head 8 to the chute or conveyingcastingfi below the head 8. Similarly material discharged from the opening of second crushingstage is conveyed along the slopingisurface 23 of the conveying casting 22 where screen.2'| and .head 8. The entire material drops through the centrally locatedopening 24 upon the screen 25 zfastened on the topof gyrating head 9. --Here again .the material isscreened and the oversized passes to the receiving openingof the third crushing stage'and that part of the material'which passes through the screen 25 drops through theopeningsinhead 9 directly to the discharge surface 26 and through the crusher dischargeopening'fl. The screens 2| and 25 and the conveying castings wear resisting materialsuch as manganese steel.

l9 and 22 are made of Protecting sleeves 28 and 28, made of wear resisting material, are placed over the gyrating shaft to protect it from wear. 7

Fig. 4 is a sectional viewof the connecting rib through :the head 8 along the lines 4-4 in Figs. 2 and 3. Fig. 4 shows the securing of screen 2| to the arms connecting the hub portiono'f'the head 8 to the rim" of head '8. The screen is fasthe screws 3il.

Fig. is similar to Fig. 2 except'that it shows the arrangement of two deck screens instead of the single screen arrangement of Fig. 2. Similar parts in the figures bear the same numbers,-but

thescreen .21 inFig.-12 isreplaced by the double it .meets the materlal which dropped through the :deck screen 2| and 2|'.. Screen 25 of Fig. 2

is. replaced .by .25' and 25"..

In Fig. 5 the material after being crushed in the first :stageqi's conveyed by the chute or conthroug'h. The main oversized material passes overthescreen 2| and drops into the receiving opening of the secondflcrushing stage. Screen 2| only allowsmaterial equal to or smallerv :than the minimumdischarge opening of the secthe double deck screens between the second and third crushing stages. In the three stage crusher of Fig. 5'the screen 25" permits material to pass through it that .has reached at this point the desired final degree of fineness.

1 If the material .being crushed is quite friable veyor 19 'tothe'inner diameter of the screen 2|. .This screen is a coarser screen than 2|" and -allows .only part of the coarse material'to'pass and the screens 2!" and 28" permit a sumcient quantity of fines to pass through them, thus by-passing the second andthird crushing stages respectively, the diameter of the heads 8 and 8 and-the corresponding concaves l6 and I! can be made of smaller diameters thus reducing not only the size of the unit and hence its cost but it also decreases the power required for the crushing op-.

It is obvious that some of the screens and their conveying surfacesin Figs.v 1, 2 and 5 may be omitted should it be desired or preferable to do so. In place of the screens manganese steel conveying surfaces such as shown in my-prior patent application above referred to should be substi tuted. V

In Fig. 7 is showna three stage crusher equipped with single deck screens and conveyors between the first and second stages and also between the second and third stages similar to the Fig.7 also-shows can be introduced and intothe third construction shown in Fig. 1. the manner in which material directly into the second stage stage without having to ceding, stages of the crusher, thus'bypassing these earlier crushing stages. Such material as is to be introduced directly into thesecond stage is admitted to hoppers 32. and from them through .openings 34 spaced circumferentially around the frame or casing l3 by which the material is fed directly into the receiving opening of the'second crusher stage. Similarly; material which is to be introduced to the third stage of the crusher is admitted into the hoppers 33 and from them through the openings 35-spaced circumferentially in the frame or casing I3, and fed directly into the receiving opening of thethird crusher stage.

In Fig. 3, which is a cross section along the line 8-8 of Fig. '7, it-shows these hoppers and openings through the frame at four places about the circumference of the crusher In Fig. 9 a partial sectional View of Fig. 1 is presented showing the position of hand holes 36 and 37. Hand hole 36 is shown placed in.line

of the discharge openingof the first crushing stage, and hand hole 31 isshown in line of the discharge opening of the second crushing stage.

These hand holes will permit an operator to remove samples of crushed material at these points. They also can be used for inspection purposes, and when properly piped water for wet crushing can be introducedat these points. In Fig. 8 two hand holes 36 are shown placed opposite each other and two hand holes 31 are also shown placed opposite each other.

In accordance with the provisions of the patent statutes, I havedescribed the principle of operation of my invention together with the apparatus which I now consider to represent the best embodiments thereof; but I' desire to have it understood that the apparatus shown is only illustrative, and that the invention'can be car ried out by other means.

pass through the pre- What I claim as new and desire to secure by Letters Patent of the United States, is,

1. In a multi-sta'ge gyratory crusher, a'gyrating shaft, a number of conical shaped heads mounted on said shaft, suitable stationary ring shaped concaves surrounding each of said heads and cooperating withthem so as toform definite crushing stages of increasing diameters from the top downward, suitable gyrating conveying surfaces between one or more stages for conveying the crushedmaterial discharged from a stage to an opening of smaller diameter than the discharge diameter of the preceding stage, suitable gyrating screens mounted on the top of the succeeding head so designed and constructed that it receives the crushed material from the said conveying surfaces and permits a substantial part of the material crushed to a finer size than the minimum clearance of the succeeding stage to pass through suitable openings in the said head, and guiding the remainder of the crushed material to the receivingopening of the-succeeding stage.

2. In a multi-stage gyratory crusher, a gyrating shaft, a number of crushing heads mounted on said shaft, stationary concaves surrounding each of said heads and coacting with them so as to form a number of crushing stages of increasing diameters and decreasing discharge openings from the top downward, gyrating conveying surfaces, slightly inclined from the horizontal and extending inwardly and downwardly, mounted on the discharge end of some .of the heads, suitable gyrating screens directly below each of the said conveying surfaces and inclined outwardly and downwardly at slight angles of inclination to the horizontaland mounted on the tops of the nextsucceeding crushing heads, each of said screens having openings equal to or less than the minimum width ,of discharge opening of the crushing stage immediately below the material discharged by a crushing stage is guided by the conveying surface to the screen below and the fines by-passthe next crushing stage and the coarse material is guided by the screens to the inlet opening of the next crushing stage.-

3. In a multi-stage gyratory crusher, a gyrating shaft, a plurality of crushing heads mounted on said shaft, stationary concaves coacting with said heads to form successive crushing stages of increasing diameters from the discharge of the crusher, conveying surfaces positioned beneath the discharge of the stage or stages preceding the final crushing stage to receive the material discharged from the next preceding stage, means connecting said conveying-surfaces to said gyrating shaft whereby the conveying surfaces will be gyrated, screens between the discharge of said gyrating conveying surfaces and the inlet of the succeeding crushing stage, said screens having openings therein equal to or less than the minimum discharge opening of the succeeding crushing stage, said crusher provided with passage-ways leading from beneath the screens past the discharge of the succeeding stage to by-pass material falling through the screens.

4. In a multi-stage gyrat'ory crusher, a gyrating shaft, a plurality of crushing heads mounted increasing diameters ,from the i' talre to the final intaketo the final discharge of the crusher, conveying surfacespositioned beneath the discharge of the stage or stages preceding the final crushing stage to receive the material discharged from the next preceding stag e, means connecting said conveying surfaces to said gyrating shaft whereby the conveying surfaces will be gyrated, screens between the discharge of said gyrating conveying surfaces and the inlet of the succeeding crushing stage, said screens having openings therein equal to or less than the minimum discharge opening of the succeeding crushing stage, the next succeeding crushing heads below said screens having vertical passages through them for receiving the material passing through the screens thus by-passing such material past the crushing stage next succeeding the screen, said screens being inclined from the discharge of the conveying surfaces to the inlets of the succeeding stages whereby the material delivered upon the screen which does not pass through it will be delivered to the succeeding crushing stage.

5. In a multi-stage gyratory crusher, a gyrating; shaft, a plurality of crushing heads mounted onsaid shaft, stationary concaves coacting with said heads to form successive crushing stages of 7 increasing diameters from the intake to the final discharge of the crusher, conveying surfaces positioned beneath the discharge of the stage or stages preceding the final crushing stage to receive the material discharged from the next preceding stage, means connecting said conveying surfaces to said gyrating shaft whereby the conv veying surfaces will be gyrated, screens between the dischargeof said gyrating conveying surfaces and the inlet of the succeeding-crushing stage, said screens having openings therein equal to or less than the minimum discharge opening of the succeeding crushing stage, the next succeeding crushing heads below said screens having vertical passages through them for receiving the material passing through the screens thusgby-passing such material past the crushing Stage next succeeding the screen, said screens being inclined from the discharge of the conveying surfaces to the inlets of the succeeding stages whereby the material delivered upon, the screen which does not pass through it will be delivered to'the succeeding crushing stage, said screens being connected to said gyrating crushing heads for gyratory movement therewith.

6. In a multi-stage gyratory crusher, a ating shaft, apluralitylof crushing heads mounted on said shaft, stationary concaves coacting with said heads to form'successive crushing stagesof increasing diameters from the intake to the final discharge of the crusher, conveying surfaces positherethrough opening out beyond the discharge of the respective stage, screens over the inlet ends of said passages for, receiving thereon the material discharged from the preceding stage, said screens shaped to form a' conveying surface to convey,

material delivered thereon which does not pass surfaces will be gyrated, said crushing through the screens to the inlet of the crushing stage while the material falling through the screens passes through the passage in the crushing head. '7. In a multi-stage gyratory crusher, a gyrating shaft, a plurality ofcrushing heads mounted on said shaft, stationary concaves coacting with said heads to form successive crushing stages of increasing diameters from the intake to the final discharge of the crusher, said crushing heads having imperforate crushing surfaces and the heads subsequent to the crushing head of the first crushing stage being provided with passages therethrough opening out beyond the discharge of the respective stage, screens carried by said crushing heads and gyrating therewith, said screens being positioned over the inlet ends of said passages for receiving thereon the material discharged from the preceding stage, the material falling through said screens being by-passed through said passages past the succeeding crushing stage, said screens shaped to form a conveying shaft, a plurality of crushing heads mounted said heads to form successive crushing stages of increasing diameters from the intake to the final discharge of the crusher, saidlcrushing'heads' having imperforate crushing surfaces and the on said shaft, stationary concaves co-acting with heads subsequent to the crushing: head of the l first crushing stage being provided with passages therethrough opening out beyond the discharge of the respective stage, double-deck screens" positioned over the inlet ends of said passages for receiving the material discharged from the preceding stage, said, double-deck screens arranged in pairs carried by each crushing head subsequent to the crushing head of the first crushing stage and being shaped toform conveying surfaces for delivering'material which does not pass through the screens to the inlet of the succeeding crushing stage, said double-deck screens indirectly connected-to said shaftfor gyrating movement therewith. I v V I 9. A gyratory crusher having two 1 or more crusher heads mounted on a gyrating shaft and having each crusher head surrounded by a suitable stationary concave so arrangedrand constructed that each crusher, head together with its corresponding concave forms a definite crushing stage so that the material to be crushed passes, successively from onecrushing stageto another where it is consecutively crushed to a finer size,

and havingeach successive crushing stage so designed and constructed that it has its entire crushing surface of substantially greater diam- .eters than those of the preceding stage, and having movable non-crushing means forconveying the m'aterial'to be crushed from one stage of small diameter to the succeeding stage of 'materially larger diameter, said movable non -crushing conveying means being perforated to form screens to permit fines to fall therethrough, said crusher provided with passages to receive the fines fall- J ing through the perforated conveying means to by-pass the fines the succeeding crushing stage.

I SHELDON sTEARNs. 

